This is a single-center, randomized, double-blind, placebo-controlled clinical trial to evaluate the effects of ARA 290 on glucose homeostasis in persons with pre-diabetes or early, dietary treated type 2 diabetes. The trial has two parallel arms with 12 subjects in each group, and with a 4-week-intervention period. At screening, a baseline investigation will include a physical examination and the following tests: oral glucose tolerance test (OGTT), and glycosylated hemoglobin (HbA1c).